Field of the Invention
The present invention relates to a semiconductor device and a method of manufacturing the same.
Description of the Related Art
Japanese Patent Laid-Open No. 2012-15316 describes a method of manufacturing a semiconductor device such as a solid-state image sensor. In this method, a structure in which a plurality of single-crystal silicon layers each including a semiconductor element such as a photodiode are separated by gaps is prepared, and a light-shielding film such as a tungsten film, a planarizing layer, color filters, and microlenses are formed on the plurality of single-crystal silicon layers.
In the method described in Japanese Patent Laid-Open No. 2012-15316, the light-shielding film such as a tungsten film is formed on the plurality of single-crystal silicon layers without filling the gaps formed between the plurality of single-crystal silicon layers. Accordingly, a conductive film as the light-shielding film may be formed in the gaps. Also, the degree of the formation of the light-shielding film in the gaps may change in accordance with a position in a substrate, or may change from one substrate to another. This may produce variations in characteristics of semiconductor devices such as solid-state image sensors.